Shim stock is used extensively throughout industry to fill a space between mating parts for structure. Different thicknesses of shim stock are often needed on a job, and to fill this need there are available peelable aluminum and peelable stainless steel shims. To fill the need for different amounts of space between parts, the peelable shims may be peeled down to the desired thickness and used to fill the void. Often the peelable shim stock needs to be machined, punched, or otherwise shaped before it reaches the one that will put it to use. The shim stock must be able to withstand these operations without delaminating, and yet be readily peelable to provide the proper thickness in use.
There has been a rapid rise in composite structures for use in aircraft due to the ratio of strength to weight in the composites. The composite structures also require the use of peelable shims, but unfortunately aluminum reacts with graphite, which is one of the most used reinforcing materials for composites. It was found that a non-metallic peelable shim can be used that does not react, is readily machineable without delaminating and is readily peelable for obtaining the correct thickness for specific use.